Grinding wheel truing apparatus



Nov. 7, 1939.

GRINDING WHEEL TRUING APPARATUS Filed Sept. 50, 1938 L. E. PAINE 2- Sheets-Sheet 1 LLOYD EF'HINE Nov. 7, 1939. L. E. PAINE GRINDING WHEEL TRUING APFABAT-US Filed Sept. 50, 1938 v 2 Sheets-Sheet 2 y 4 E: E

gwuexvvtom LLUYDEF'HINE Patented Nov. 7, 1939 2,178,842 GRINDING WHEEL TRUING APPARATUS Lloyd E. Paine, Worcester, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application September so, 1938, Serial No. 232,604

' I v 1 Claim. (01. 125-11 The invention relates to grinding wheel truing apparatus.

One object of the invention is to provide a truing apparatus for grinding machines so organized that two different surfaces on a grinding wheel may be dressed and trued with a given setting of the machine, and without removing the -.work piece from the machine centers. Another object of the invention is to provide a simple and practical truing attachment which may be readily mounted on existing machines. Another object of the invention is to provide truing apparatus mounted on the face plate of a grinding machine so that a minimum of adjustment will be required for the truing operation. Another object of the invention is to improve a grinding machine with an angular slide so as to facilitate'the truing of both peripheral surfaces of the grinding wheel. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the fea tures of constructions, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claim.

In the accompanying drawings in, which is shown one of many possible embodiments of the mechanical features of this invention:

Figure .1 is a front elevation of a grinding machine equipped with the wheel truing apparatus of the invention;

' Figure 2 is a plan View of the machine;

Figure 3 is an enlarged view of the truing tool; Figure 4 is a view similar to Figure 2 with the wheel truing tool in place;

Figure 5 is a front view of the face plate 20 taken along the line 55 of Figure 4.

Referring first to Figure 1, the invention may be applied to a cylindrical grinding machine of any type, but so far as certain features o the invention are concerned, it is applied to a machine having a wheel head journalling the grinding wheel spindle at an angle with the axis of the work piece. Such a machine has a base H! on the vapor surface of which, as shown in Figure 2, areparallel ways II and i2 mounting a work table 13 upon which are clamped a headstock l4 and a tailstock I5. The tailstock i5 is provided with theusual adjustable tail center It, while in the headstock is mounted a spindle, not shown, driven by a motor ll through belts and pulleys contained in a casing I8. On the front of the spindle which is journalled in the headstoik is the usual face plate 20 which is provided with a number of the usual radial T-slots, for example the T-slot 2| shown in a broken away portion of the face plate 20 in Figure 2. Projecting from the face plate 20 and coaxial with it is the usual head center 22. 8

The machine may be equipped with any usual or preferred mechanisms for traversing the table i3 along the ways H and I2. For example, there may be provided, as shown in Figure I, a rack 24 secured to the under side of the table or carriage 10 53 with which meshes a pinion gear 25 fastened to a stud shaft 26 which has likewise fastened to it a gear 21 which meshes with a pinion gear, not shown, on the shaft of ahand wheel 30. Thus, the operator, by turning the hand wheel 30, may 15 readily traverse the table or carriage i3 and with it the work piece W, but it will be understood that mechanical or hydraulic traversing mechanisms might be substituted.

The machine is equipped with a cross slide 35 W mounted on the usual ways, not shown, and having secured on its under side, as shown in dotted lines in Figure 2, a half nut 36 engaged by a cross feed screw shaft 31, a non-threaded part of which extends to the front of the machine and has 23 there, fastened to it a gear 38 meshing with a gear 39 (shown in dotted lines in Figure 2), which gear, as best shown in Figure l, meshes with a pinion t0 fastened to a ratchet-wheel 4| which may be operated by a pawl d2 that is capable of m being moved manually or automatically by means of a solenoid 63. The foregoing or any other suitable cross feeding mechanism is provided to feed the wheel slide 35 in a direction transverse to the direction of movement of the table or car- 25 riage i3. Usually such transverse direction is a direction perpendicular thereto, as illustrated in the present case.

For the grinding of shafts with shoulders or the like, it is desirable to provide an apparatus 4% which will grind the cylindrical portion of the shaft as well as the radial shoulder itself and will grind each of them to the corner. The machine accordingly is provided with a grinding wheel 45 whose periphery constitutes two coni- 45 cal surfaces 46 and 61, the-included angle of the cones being 90 and elements of the cones being at angles of 45 to the axis of the wheel and the conical surfaces being of like dimensions and area. This wheel is mounted upon a wheel spin- 50 dle 50 journalled in a wheel head 5| with the axis of the spindle at 45 to the axis of the screw shaft 31. Mounted on the wheel head 5| is a motor connected to the spindle 50 by suitable belts and pulleys all encased in a casing 60. 53

According to the present invention I provide a truing tool having one or more wheel truing points (preferably diamonds), which truing tool may be mounted in a T-slot 2| of the face plate 20. As shown in Figure 3, this truing tool comprises a stud 10 having an enlarged threaded portion II and a head 12. I provide a nut 13 fitting on the threaded portion ll together with a washer 14. At the left-hand end of the stud I is an axial hole 15. Near the left-hand end of the stud 10 is a transverse hole 16. I provide a diamond truing nib TI. This nib has a shank 19 which will fit in either of the holes I5 and I8. Set screws 8| and 82 hold the nib Tl in place by engagement with the shank 19. The nib Tl has an embedded diamond as for truing the wheel 46.

The work piece W shown is a shaft having an irregular end portion W' the face of which is to be ground to a plane surface, the shaft of the work piece being ground to a cylindrical surface. The stud 10 functions as.a work driving dog to rotate the work piece as shown in Figure 2. Considering the parts in the position shown in Figure 2, the operator can, quickly rotate the ratchet wheel 4| (by hand) feeding.

the grinding wheel into the work piece and can readily grind the left hand face of the part W as well as the cylindrical surface of the work piece W. When the operator desires to true the grinding wheel he first stops the rotation of the work piece with the truing tool 10 in the horizontal plane of the center 22 and on the back side of the work piece then advances the work piece a quarter tu.rn. The parts can be put in this position in any manner desired. This clears the work piece away from the truing tool. Assuming that the nib is in the hole the operator can readily true the face 41 of the grinding wheel by moving it across the face of the nib. Then he can shift the nib to the hole 16 and true pieces can be removed from the machine without upsetting the set-up for the truing operation. The brake in the work head holds the truing tool rigidly enough for the truing operation. The truing tool has a double function as a truing tool and a driving dog. The subject matter of the inventionis particularly advantageous when embodied in hand traverse grinders where a simple set-up is important for speedy operation and effective control.

It will thus be seen thatthere has been provided by this invention an apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

In a grinding machine, awork head, a rotatable face plate, a stud, means to hold said stud in the face plate to'act as a driving dog, means in the stud to hold a truing nib, a cross slide, and a wheel spindle mounted at an angle on said cross slide.

LLOYD E. PAINE. 

